A computerized system of a computing system implementing a .NET framework and useful for instrumenting virtual-machine-based applications includes a computer store containing data, wherein the data comprises: a native library; a computer processor in the computerized system, which computer processor: provides a virtual machine with a Just-In-Time Compilation function; loads the native library into a process memory; redirects the Just-In-Time Compilation function to a custom implementation, wherein the custom compilation function: creates a representation of one or more methods being compiled; and compares the one or more methods against a policy of methods to be instrumented; and determines that one or more methods match the policy of methods to be instrumented.